X86Disassembler: if verbose logging is going to nulls(), disable logging completely.

Otherwise we'll spend a ridiculous amount of time pretty printing debug output and then discarding it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140276 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed